A number of different kinds of responses can be obtained from the
application of various growth regulators. The response varies with the chemical and the
condition or stage of development of the tree and fruit. Therefore, before you apply a
chemical you should understand how it affects the tree or crop and the important side
effects.

The degree of effect depends on how much of the material is absorbed and the condition
of the tree. Factors such as cool weather, slow drying conditions, and good foliage will
increase the response. Although poor foliage reduces absorption, weak trees will generally
be overly sensitive to even small amounts of growth regulators. Concentrating sprays
increases the concentration of the chemical, which can cause injury. Similarly, adding a
surfactant, unless so indicated, can result in greater absorption and possible injury.